1. Field of the Invention
The present invention relates to a charging member for use in contact charging of an electrophotographic apparatus, a process cartridge, and an electrophotographic apparatus.
2. Description of the Related Art
A charging member that abuts an electrophotographic photosensitive member to charge the electrophotographic photosensitive member is generally formed so as to have a rubber-containing elastic layer in order that an abutment nip between the electrophotographic photosensitive member and the charging member may be sufficiently and uniformly secured. As such elastic layer ineluctably contains a low-molecular weight component, the low-molecular weight component may bleed toward the surface of the charging member owing to long-term use of the charging member to contaminate the surface of the electrophotographic photosensitive member. To cope with such problem, Japanese Patent Application Laid-Open No. 2001-173641 proposes a configuration in which the peripheral surface of an elastic layer is coated with an inorganic oxide coating or an inorganic-organic hybrid coating so that the bleeding of its low-molecular weight component toward the surface of a charging member may be suppressed.
By the way, in association with a recent increase in the speed of an electrophotographic image forming process, the time period for which an electrophotographic photosensitive member and a charging member contact each other has become relatively short, which is disadvantageous for stable and secure charging of the electrophotographic photosensitive member. It can be said that, under such circumstance, a charging member having a thick film, which is intended for the suppression of the bleeding of its low-molecular weight component, formed on its peripheral surface is of a disadvantageous configuration for stable and secure charging of an electrophotographic photosensitive member.